陈丽燕,雷廷武,董月群,颜燕.不同示踪法测量砾石层中水流流速研究[J].农业机械学报,2015,46(4):141-146.
Chen Liyan,Lei Tingwu,Dong Yuequn,Yan Yan.Estimating Velocity of Water Flow within Gravel Layer by Different Tracer Methods[J].Transactions of the Chinese Society for Agricultural Machinery,2015,46(4):141-146.
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不同示踪法测量砾石层中水流流速研究   [下载全文]
Estimating Velocity of Water Flow within Gravel Layer by Different Tracer Methods   [Download Pdf][in English]
投稿时间:2014-06-10  
DOI:10.6041/j.issn.1000-1298.2015.04.021
中文关键词:  砾石层  平均流速  优势流速  最大流速  电解质示踪法
基金项目:国家自然科学基金资助项目(41230746)
作者单位
陈丽燕 中国农业大学 
雷廷武 中国农业大学 
董月群 中国农业大学 
颜燕 中国农业大学 
中文摘要:采用室内试验,用平均粒径约2cm的砾石,在长4m、宽15cm、高50cm的水槽内堆积厚为5cm的砾石层,在坡度为4°、8°、12°和流量为3、6、12L/min条件下,距离电解质脉冲发生器0.3、0.6、0.9、1.2、1.5m处放置探针,测量电导率变化过程,计算水流的最大流速、优势流速和平均流速,并用染色剂示踪法对比砾石层中水流的最大测量流速。结果表明,试验所用各工况,流量对流速的影响不显著,坡度增大,流速明显增大。试验条件下,水流的优势流速变化范围为0.031~0.070m/s,优势流速与最大流速的比值稳定,在0.81~0.83之间。平均流速与优势流速的比值随坡长的增加逐渐增大,增长的速率逐渐减小并趋于稳定。平均流速与最大流速的比值在0.68~0.78之间,并随距离的增加稍有增大。
Chen Liyan  Lei Tingwu  Dong Yuequn  Yan Yan
China Agricultural University,China Agricultural University,China Agricultural University and China Agricultural University
Key Words:Gravel layer  Mean velocity  Peak velocity  Leading edge velocity  Electrolyte tracer method
Abstract:Mountainous soils often contain large amounts of gravels which impact rainfall infiltration, runoff and soil erosion. The flow velocity within gravels is of great importance for research of soil erosion process in rocky mountainous areas. Dye tracer method was commonly used to measure the leading edge velocity. The gravels of about 2 cm in diameter were used to fill to a thickness of about 5cm in a flume of 4m long, 15cm wide and 50cm high. Five sensors were used to measure the electrolyte conductivity change process at 0.3, 0.6, 0.9, 1.2 and 1.5m from the solute injector under three flow rates of 3, 6 and 12L/min and three slope gradients of 4°, 8°and 12°. The peak, mean and leading edge velocities were computed before comparisons were made with those measured by using dye tracer method. The results showed that under different conditions, flow velocity was not significantly affected by discharge rate, but notably affected by slope. With the increase in slope, flow velocity increased from 0.031m/s to 0.070m/s. The peak velocities were 0.81~0.83 times of the leading edge velocity, regardless of the effect of slope and flow rate. Mean velocities were about the same as the peak velocities, which were 0.68~0.78 times of the leading edge velocities and increased with distance increasing. The ratio of mean velocity and leading edge velocity can be also used to calculate the flow velocity within gravels measured by dye tracer method. The method should be useful to understand the hydrodynamics of water flow within gravel layers.

Transactions of the Chinese Society for Agriculture Machinery (CSAM), in charged of China Association for Science and Technology (CAST), sponsored by CSAM and Chinese Academy of Agricultural Mechanization Science(CAAMS), started publication in 1957. It is the earliest interdisciplinary journal in Chinese which combines agricultural and engineering. It always closely grasps the development direction of agriculture engineering disciplines and the published papers represent the highest academic level of agriculture engineering in China. Currently, nearly 8,000 papers have been already published. There are around 3,000 papers contributed to the journal each year, but only around 600 of them will be accepted. Transactions of CSAM focuses on a wide range of agricultural machinery, irrigation, electronics, robotics, agro-products engineering, biological energy, agricultural structures and environment and more. Subjects in Transactions of the CSAM have been embodied by many internationally well-known index systems, such as: EI Compendex, CA, CSA, etc.

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